Electric heating unit



C. C. ABBOTT.

ELECTRIC HEATING UNIT. APPLICATION mzo JUNE 20, 1918.

1 3 50 9 1 O Patented Aug. 24, 1920.

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UNITED STATES PATENT OFFICE.

ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC HEATING UNIT.

Application filed June 20,

To all whom it may concern:

Be it known that I, CHARLES C. ABBOq'r, a citizen of the United States,residing at Pittsfield, in the county of Berkshire, State ofMassachusetts, have invented certain new and useful Improvements inElectric Heating Units, of which the following is a specltication.

My invention relates to an electrical heating unit and more particularlyto such a unit in which sheathed wire is used and 1t has for its objectthe improvement in a device of this character.

My invention will best be understood by reference to the accompanyingdrawing in v which Figure 1 is a longitudinal section, partially inelevation, of one form ofheating unit embodying my invention; Fig. 2 1sa side view thereof and Fig. 3 is a detail sectional view showing asection of the sheathed wire with an enlarged terminal.

Referring now to the drawings, 10 is a metal core member, preferablyprovided with enlarged cylindricalends as shown at 11 and 23. Theresistance element is formed of sheathed wire 12 comprising a resistancecore 13 inclosed in a metal sheath 14 with an intervening layer ofrefractory insulating powder, such as magnesia 15, insulating the corefrom the sheath. The sheathed wire is preferably square in cross sectionand is tightly wound on the contracted portion of the core 10. sheathedwire of this character is commonly provided with an enlarged terminalwhich I have indicated at 16, the core 13 and sheath 14 of. the terminalbeing continuous with the core and sheath of the sheathed wire proper.The insulating material of the terminal is indicated at 15*. Adjacentthe enlarged end 23 the core is reduced and tapered as at 17. Thesheathed wire is tightly wo'und on the contracted portion of the core10, the enlarged terminals being disposed adjacent the beveled portion17 of the member so as to form a close fit between the core and thesheath 12. hen both terminals of the re sistance wire are brought out atthe same end of the unit, as disclosed in the form of my inventionillustrated in the drawings, the free looped end 18 of the sheathed wiremay conveniently be secured in position by a pin 19 which is inserted inan opening formed for this purpose in the core member. The space betweenthe enlarged section 11 Specification of Letters Patent.

.is flush with by means of collar parent that a heating Patented Aug.24, 1920.

1918. Serial No. 241,061.

of the core and the solid winding of the sheathed wire is preferablyfilled with a heat conducting material 20, such as iron cement. alsobuilt up into a cylindrical form which the outside diameter of thesheathed wire by means of a similar cement .21 which closely surroundsthe terminals and holds the same against the core. The unit thus formedis preferably surrounded with a metal sheath 22, the end of the sheathadjacent the terminals being sealed 23 provided with openmgs 24 throughwhich the enlarged terminals pass. The opposite end of the sheath 1ssealed and made water tight by the enlarged section 11 of the core. Thesheath is then compressed, preferably by swaging, sufiiciently to bringthe same into intimate thermal relation with the sheathed wire so as topromote the transfer of heatfrom the core to the sheath, which sheatha'ctsas the heat distributing member. It will be a 4 unit made inaccordance with my invention is small and compact and will readily wireand may be used in a variety of ways, among others as trated. The uniting formed in a heat distributing member for the reception of the sameor it may be used as an immersion heater or otherwise.

While I have herein shown and described one modification of myinvention, I do not desire to be limited to the exact arrangement shownand described but seek'to cover in the appended claims all thosemodifications which come within the true spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. An electric heating device comprising a metal core and a sheathedwire heating element surrounding the core, the core and heating elementbeing worked into intimate contact.

2. An electric heating device comprising a metal core, a sheathed wireheating element surrounding the core and a metal sleeve inclosing theheating element; the core, heating element and sleeve being worked intointimate contact.

3. An electric heating device comprising a core member, a sheathed wirereslstance he opposite end of the unit is an ordinary unit as illusmaybe placed in an open'.

element tightly wound on said core member and a metal sleeve inclosingthe resistance element and compressed into good thermal relationtherewith.

4E.;\n electric heating device comprising a core member, a sheathed wireresistance element square in cross section closely Wound on said coremember, and a metal sleeve surrounding the resistance element and inclose thermal relation therewith.

5. An electric heating unit comprising a core member, a sheathed wireresistance element Wound on said member, a metal sleeve inclosing theresistance element and worked into good thermal relation therewith, anda member closing one end of the sleeve and provided with openingsthrough which the of the core and occupying the space between the coreand the metal sheath.

In witness whereof I have hereunto set my hand this 17th day of June,1918.

CHARLES C. ABBOTT.

